Both oral and intravenous forms of drug delivery have a number of limitations. Oral delivery limitations include toxicity, poor absorption and varying concentrations over time. Intravenous limitations include the requirement to mix and store the drug in liquid form as well as the use of sterile technique. These can be particularly problematic in rural areas where adequate refrigeration and sterile needles are not necessarily readily available, limiting shelf life and exposing the patient to infection. Thus, there is a need for improved methods of drug delivery which can extend shelf life and are more easily used in settings lacking refrigeration or sterile medical supplies.
An additional challenge in drug delivery is administrating a medication regimen which requires an initial delivery of a medication (e.g. drugs, vaccines and other therapeutic agents) followed by one or more subsequent “booster shot” dosages of medication, significantly later in time, in order to complete the medication regimen. Such a regimen adds time and costs to all concerned as well the risk that the subsequent dose is administered late or missed altogether. Administration of such a medication regimen can be particularly problematic in rural areas where there is logistical difficulty in finding and/or treating a patient with one or more subsequent dosages.
Some of the same challenges also present themselves in inoculating livestock with a medication that requires one or more booster shots. Administering a dosage of medication requires herding the livestock followed by the isolating and pacifying of each individual animal in order to deliver the medication dosage. Administering a booster shot dosage in the same manner to the same livestock requires the effort and cost of herding the livestock and the isolating and pacifying of each individual animal one or more subsequent times. This challenge can also be seen in providing medication to humans, where the patient may be unable to return to a doctor to receive a second, third, and/or subsequent booster shot as part of a medication regimen.
Thus, there is a need for improved methods of medication delivery which can deliver subsequent dosages of a medication regimen without the need for the patient (which can include a human or other animal such as bovine livestock) to return to the administrator of the initial medication, or for the administrator of the initial medication to actively seek out and find the patient.